The subject matter disclosed herein relates generally to imaging systems, and more particularly, to a method and system for performing image background selection.
In an oncology examination, a patient may go through a series of examinations, using for example, a computed tomography (CT) system, a positron emission tomography (PET) system, an ultrasound system, an x-ray system, a magnetic resonance (MR) system, a single photon emission computed tomography (SPECT) system, and/or other imaging systems. The series of examinations is performed to continuously monitor the patient's response to treatment. When evaluating a patient's response to treatment, the previous and follow-up examinations are often analyzed together. The results from the analysis of the follow-up examination may be saved together with results of the analysis of the previous examination(s). Accordingly, information on the progression of the disease throughout the whole series of examinations may be available to the clinician at any time from the same file and/or location.
However, when analyzing PET images to determine the progression of a disease, it may be difficult to identify the boundaries of an object of interest, such as for example, a lesion, when comparing the lesion for the same patient over time. As a result, a segmentation tool may be utilized to segment the lesion to enable the operator to determine the changes in the lesion over time.
At least one known segmentation tool separates the lesion from the normal background uptake in the patient and as such relies on sampling the normal uptake or background levels in the examination. In addition, when monitoring lesions over time, it is important to ensure consistent approaches are taken to lesion segmentation especially given that many factors may affect the background uptake levels.
Recent developments in therapy response monitoring, such as PERCIST (PET response criteria in solid tumors), rely on a more standardized approach to the process of classifying uptake at a lesion. The standardized approach may include, for example, specifications of uptake thresholds and techniques for background sampling that may include recommendations for locations and the sampling method. However, the standardized approach may be labor intensive and involve localizing the desired anatomy and then selecting and sizing the sampling tool. Moreover, additional steps may include fine tuning of the sampling region and pre to post therapy comparison and analysis of the results.